1. Field of the Invention
The invention relates to liquid crystal display technology and in particular to an array substrate for a liquid crystal display (LCD) and a method for fabricating thereof, in which the array substrate comprises a pixel structure with high aperture ratio (AR).
2. Description of the Related Art
Liquid crystal displays (LCDs) are widely employed as a flat panel display in electronic products, such as portable personal computers, digital cameras, projectors, and the like, due to thin profile and low power consumption characteristics of LCDs,
A typical LCD includes an array substrate, a color filter (CF) substrate, and a liquid crystal layer disposed therebetween. The array substrate contains a plurality of matrix pixels correspondingly connecting to a plurality of data lines and a plurality of scan lines, and a plurality of pixel driving circuits consisting of a plurality of electric devices, such as thin film transistors (TFTs) and storage capacitors. A TFT is employed for applying a voltage to a pixel. A storage capacitor is employed for maintaining pixel information during a nonselective period of voltage application. For conventional array substrate fabrication, the storage capacitor uses the common electrode as an upper or lower electrode, which is in the pixel region and parallel to the scan line. Moreover, the area of the common electrode is large to obtain a storage capacitor having a large capacity.
However, since the common electrode typically comprises opaque metal, the aperture ratio (AR) of the pixel is reduced when the area of the capacitor electrode is increased for increasing the capacity. Thus, the power of the backlight module must be increased to maintain the brightness of the LCD. As a result, power consumption is increased.
Therefore, there exists a need for an improved array substrate capable of increasing AR of the pixels while maintaining the capacity of the storage capacitors.